1. Field of the Invention
The present invention is related to a vibrating gyroscope and, more particularly, to the type of vibrating gyroscope that can be applied for a navigation system providing an appropriate guidance of a vehicle by detecting the position of a moving body by sensing its rotational angular velocity, or to the type of vibrating gyroscope that can be applied for a damping system such as preventing device for preventing shaking of hands that suppresses vibration by detecting an external vibration.
2. Description of the Prior Art
FIG. 6 is an exploded perspective view showing an example of a conventional vibrating gyroscope.
The conventional vibrating gyroscope 1 shown in FIG. 6 includes a regular triangular prism-shaped vibrating body 2 made of a constant-elastic metal material such as elinver. On three side faces of the vibrating body 2, piezoelectric elements 3a, 3b, 3c are secured respectively by suitable means such as an adhesive(not shown).
The piezoelectric elements 3a, 3b, 3c are made, for example, by forming electrodes on both surfaces of a piezoelectric ceramics. An oscillation circuit (not shown) described later is connected between the piezoelectric elements 3a, 3b and the piezoelectric element 3c.
Two supporting members 5a and 5b made of metal wire are mounted on ridge-line portions in the vicinity of the nodal points of the vibrating body 2. Each of the supporting members 5a and 5b consists of a pair of legs 6, 6 and a connecting member 7 between two legs 6, 6, and is shaped like a U-shape in cross section. The legs 6, 6 of the supporting members 5a and 5b are mounted on a rectangular-shaped supporting board 10 and each of the connecting members 7 are mounted on the ridge-line portions in the vicinity of the nodal points of the vibrating body 2.
The supporting board 10 has two foot members 11, 11 extending downward from its both ends in the longitudinal direction. Each of the foot members 11, 11 has a projecting piece 11a extending downward from the center of the bottom end of the foot member 11. Two projecting pieces 11a, 11a of the supporting board 10 are inserted into two holes 12a, 12a formed on a circuit board 12. The vibrating body 2 and the supporting board 10 are housed in a case 15.
Circuit components 13, 13 containing an oscillation circuit and a detection circuit are mounted on the circuit board 12. By a signal from the oscillation circuit, the vibrating body 2 bends and vibrates in the direction perpendicular to the face on which the piezoelectric element 3c is formed. In this situation, when a rotation is applied around the central axial direction of the vibrating body 2, a vibration direction of the vibrating body 2 changes by a Corioli's force, according as a change of the vibration direction, a difference is generated between output voltages of the piezoelectric elements 3a and 3b. Thus, a rotational angular velocity applied to the vibrating gyroscope 1 can be detected by measuring the difference of the output voltages.
However, since the vibrating body 2, the supporting members 5a and 5b, the supporting board 10 and the circuit board 12 are constructed to a vertical direction in the conventional vibrating gyroscope 1, it is tall, that is to say, it takes a large space in the vertical direction. Thus, when mounting the vibrating gyroscope 1 in the other device, it occupies large space in the vertical direction. This had been an obstacle to miniaturization of the device. Moreover, a manufacturing process had been complicated because the above each members are constructed to the vertical direction in the conventional vibrating gyroscope 1.